Randomized, placebo-controlled, parallel-group, double-blind, multiple-dose, activity and safety clinical study of SRT2104 administered orally once daily for 28 consecutive days. This will be an inpatient/outpatient study to assess the safety and pharmacokinetics (PK) of SRT2104 in type 2 diabetic (T2D) male and female subjects on an existing, stable, background metformin therapy. Approximately 112 subjects aged 18-65 years, who fulfill the inclusion/exclusion criteria, will be screened for this study to enroll approximately 80 subjects. Subjects will be evenly randomized to receive SRT2104 2.0 g/day or placebo approximately 15 minutes following consumption of a standardized morning meal. Subjects will remain on a fixed dose of test material for all dosing days in the study.